What occurs to metal gusset plates during a fire when wood burns away?

During a fire, when wood components of a truss system burn away, the metal gusset plates can indeed fall out and lose structural support. Gusset plates are designed to connect wooden members in a truss; when the wood around them is consumed by fire, the structural integrity of the entire system is compromised.

As the wood deteriorates, the gusset plates may not have sufficient structural support to remain attached, leading to them disengaging from the trusses. This disconnection can result in a collapse of the truss itself since the weight of the roof or floor above can no longer be adequately supported without the wooden components. This phenomenon highlights the vulnerability of metal connectors in a fire scenario where their effectiveness is heavily reliant on the integrity of the wooden members they support.